1. Field
One or more exemplary embodiments of the present disclosure relate to photon counting apparatuses and methods, and radiographic imaging apparatuses comprising the same.
2. Description of the Related Art
A radiographic imaging apparatus is an imaging system for obtaining images of an inside of an object, such as a human body or an article, by irradiating the object with radiation such as an X-ray. Such a radiographic imaging apparatus includes a radiation detector configured to detect the radiation irradiated to the object.
The radiographic imaging apparatus may include a photon counting apparatus that uses a photon counting detection (PCD) method of counting radiation photons incident to the radiation detector. For example, a photon-counting type X-ray detector includes a photoelectric conversion material unit configured to convert input X-ray photons into electric charges, and a readout circuit unit configured to count the electric charges converted by the photoelectric conversion material unit. Electric charge packets generated in the photoelectric conversion material unit reach an input end of the readout circuit unit due to an internal potential difference. After reaching the input end of the readout circuit unit, the charges are voltage-amplified in an amplifier, and are counted according to size in an internal comparator and counter after passing through an additional amplifying or shaping process.
By using an asynchronous ripple binary counter, the readout circuit unit increases data by a count value of one each time a photon is incident to the radiation detector, and finally reads a data value at a point in time when X-ray photons are incident and reconstructs the data value to form an image.